Post-combustion CO2 capture: On the potentiality of amino acid ionic liquid as modifying agent of mesoporous solids

In this paper, mesoporous gamma-Al2O3 was impregnated with [Emim][Gly] ionic liquid (IL) at different loadings (5, 9 and 16% wt). The obtained sorbents were tested for CO2 capture under typical conditions of combustion flue-gas at temperatures varying in the range 303-373 K. N-2 porosimetric analysis on the samples, coupled with kinetic tests of CO2 adsorption, revealed that a lower pore volume occurring at the highest IL loading ended up in a slower saturation process. The enhancement of CO2 capture capacity of the raw sorbent was monotonic with the IL loading and the best results were achieved at 303 K. The chemisorption nature of the adsorption process for IL-containing sorbents was assessed by means of FT-IR analysis. Finally, preliminary tests of cyclic adsorption/desorption showed that nearly 80% of the original CO2 capture capacity of sorbent was restored by steam desorption at 388 K.